“Organic” superconductors are part of the organic conductor family which includes molecular salts, polymers and pure carbon systems (including carbon nanotubes and C60 compounds). The molecular salts within this family are large organic molecules that exhibit superconducting properties at very low temperatures. For this reason they are often referred to as “molecular” superconductors. Their existence was theorized in 1964 by Bill Little of Stanford University. But the first organic superconductor (TMTSF)2 P6 was not actually synthesized until 1980 by Danish researcher Klaus Bechgaard of the University of Copenhagen and French team members D. Jerome, A. Mazaud, and M. Ribault. About 50 organic superconductors have since been found with Tc's extending from 0.4 K to near 12 K (at ambient pressure). Since theses Tc 's are in the range of Type I superconductors, engineers have yet to find a practical application for them. However, their rather unusual properties have made them the focus of intense research. These properties include giant magnetoresistance, rapid oscillations, quantum hall effect, and more (similar to the behavior of InAs and InSb). In early 1997, it was, in fact (TMTSF)2PF6 that a research team at SUNY discovered could resist “quenching” up to a magnetic field strength of 6 tesla. Ordinarily, magnetic fields a fraction as strong will completely kill superconductivity in a material.
Organic superconductors are composed of an electron donor (the planar organic molecule) and an electron acceptor (a non-organic anion). A few examples of organic superconductors include:                (TMTSF)2 ClO4 [tetramethyltraselenafulvalene+acceptor]        (BETS)2 GaC14 [bis(ethylenedithio)tetraselenafulvalene+acceptor]        (BEDO-TTF)2 ReO4H2O        [bis(ethylenedioxy)tetrathiafulvalene+acceptor]        
How small can a sample of superconducting material be and still display superconductivity? This question is relevant to the fundamental understanding of superconductivity, and also to applications in nanoscale electronics, because Joule heating of interconnecting wires is a major problem in nano-scale devices. It has been shown that ultrathin layers of metal can display superconductivity, but any limits on the size of superconducting systems remain a mystery. (BETS)2GaCl4, where BETS is bis(ethylenedithio)tetraselenafulvalene, is an organic superconductor, and in bulk it has a superconducting transition temperature Tc of ˜8 K and a two-dimensional layered structure that is reminiscent of the high-Tc cuprate superconductors.
Organic superconductors are regarded as unconventional superconductors because their properties cannot be explained by the Bardeen-Cooper-Schrieffer (BCS) theory that describes low-temperature superconductors such as lead and bismuth. Although scanning probe methods have provided unprecedented real-space information on both low-Tc BCS superconductors and high-Tc cuprate superconductors, there have only been a handful of reports of scanning tunneling spectroscopy measurements on layered organic superconductors. Moreover, direct visualization of the detailed molecular structures and local spectroscopic mapping of these systems has not yet been performed.